In carrying out the crop loosening procedure pursuant to the above-mentioned application, a relatively small, hook-shaped tool is inserted up into the neck of the carcass to loosen and dislodge the crop from tissues within the neck before the crop and the rest of the organs of the alimentary tract are then removed as a complete package through an opening at the posterior of the carcass. It has been determined that, for best results, the tool should be inserted into the side of the neck through a longitudinal slit in the skin. The tracheae and esophagus housed within the neck chamber should not be severed or damaged.
Heretofore, others have attempted to prepare the slit using a knife blade that swings into engagement with the neck skin and then moves in a longitudinal slitting stroke away from the shoulders of the carcass generally parallel with the neck axis. A positioning yoke situated immediately below the knife blade and moveable with the blade engages the neck immediately before the knife blade and in leading relationship to the blade as the slitting stroke is carried out so as to keep the neck properly located with respect to the blade.
However, it has been found that, particularly because the heads of the carcasses have already been removed by this stage of the processing operation, the neck skin has a tendency to shrivel and retract up along the underlying stump of the neck, making it difficult to accurately and effectively carry out the slitting operation.